Hexagon Fractional Die, National Coarse Thread, 3/4-In. x 103 4" x 10, national course thread, 1 7 16" hexagon fractional die, carbon steel, ideal for routine maintenance, repair work & for rethreading where high accuracy & tolerance thread is not critical, recommended for use with hexagon die stock, die can be used with a wrench or socket when space is limited , designed for hand threading work in a variety of materials.